SKM 2021 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 8: Poster Session II

HL 8.16: Poster

Tuesday, September 28, 2021, 10:00–13:00, P

Full Wafer Property Control of Local Droplet Etched GaAs Quantum Dots — •Hans-Georg Babin, Nikolai Bart, Marcel Schmidt, Andreas D. Wieck, and Arne Ludwig — Ruhr-Universität Bochum, Germany

Local droplet etched GaAs quantum dots (LDE-QDs) are a promising candidate for excellent single and entangled photon sources. Taking further steps towards application, this requires structures of increasing complexity, engineering the electronic and photonic environments of the QDs. Therefore, it is important to get perfectly matched QDs for the required photonic structures. In this submission, we show a way to compensate for non-perfectly adjusted growth conditions and to accelerate required parameter studies.

We induce certain flux gradients by stopping sample rotation and using the parallax of the effusion-cells. This results in a gradual change of deposited material and cell flux, as well as an induced surface roughness modulation. By this we can vary properties of the QDs like density and emission wavelength over the hole wafer range. Additionally, we induce a stripe patterned density modulation, which was shown before with Stranski-Krastanov QDs. As an example, the widest achieved wavelength shift of the ground state emission energy at 100 K, measured by photoluminescence spectroscopy, extends over the range of 795 nm to 737 nm. The change in surface roughness leads to an additional periodical modulation of the ground state of approximately 3 nm on a mm scale.